I just upgraded from 11.04 to 11.10 and after restart it showed the login screen. After login, only the desktop background shows with ubuntu 11.10 text at the bottom-left corner.
Did my GNOME stop working ?
My mouse pointer moves though, so its not a system crash.

I logged into 2D and did unity --reset. All the desktop items and left hand menu bar vanished. I logged as normal ubuntu and desktop was still blank. But, if I login to tty (CTRL+SHIFT+1) and logout, my desktop items showup but the menu bar is missing. Also, if I open a textfile from the desktop, gedit pops up with the application's menu bar.
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anjaneshNov 4 '11 at 2:20

@anjanesh are you able to log into Unity 2D? It sounds to me like Unity is crashing. If you can log in to the recovery console (from the log in screen), run unity and post the output it gives in your question. You might need to run gnome-terminal from the recovery console in order to capture the output.
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RolandiXor♦Nov 4 '11 at 3:23

I am able to log into Unity 2D. Im using it right now.
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anjaneshNov 4 '11 at 4:19